Electrostatic Induction

Q. Explain repulsion is the sure test of electrification?

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Q.

Explain what happens when amber is rubbed with wool or silk.

Q.

What happens when amber is rubbed with fur?

1. Amber acquires a negative charge

2. Amber acquires a positive charge

3. Cannot be determined

4. Amber acquires no charge

Q.

When a plastic scale rubbed on dry hair is kept close to small paper pieces, it attracts the paper pieces. When the rubbed portion of scale is touched with hand, the pen looses attractive nature. Give reason for this.

Q.

When a plastic refill is rubbed with polythene, which object acquires an electric charge?

Q.

Question 20

You might have observed on a dry day that when you touch the screen of a television or computer monitor (with picture tube), you get a slight shock. Why does it happen?

Q.

What is the difference between conduction and induction?

Q. if two baloons are rubbed together. will they attract or repel

Q.

Explain charging by rubbing

Q.

What is charging by induction ?

Q. When a glass rod is rubbed with a dry silk cloth, the charge acquired by the silk cloth is:

1. Positve
2. Negative
3. Both positive and negative
4. None of the above

Q.

When we rub one of the given objects on dry hair and place it close to small pieces of paper, they get attracted. Spot that object. Give reason why only that object attracts and other objects don't attract.
(i) Metal pen (ii) Finger of hand (iii) Plastic scale [3 MARKS]

Q.

Does the electric field exert force?

Q.

James combs his hair and brings the comb near some tiny pieces of paper. He finds that the comb is attracting the pieces of paper. The force of attraction on the tiny piece of paper by the comb is due to which one of the following forces?

1. Magnetic force

2. Gravitational force

3. Nuclear force

4. Electrostatic force

Q.

The leaves of a gold-leaf electroscope are made of brass.

1. True
2. False

Q.

When a charged glass rod rubbed with silk is brought near a charged plastic straw rubbed with polythene, there is an attraction between the two. Identify the charge on the plastic straw.

1. Positive

2. Negative

3. Neutral

4. Can't say

Q. Two charged objects are brought close to each other. For the two charged objects, choose the most appropriate statement from the following options.

1. They will only attract each other
   
2. They will only repel each other
   
3. They may attract or repel depending on the type of charges they carry
4. There will be no interaction between the two charged objects

Q. It is observed that when a brush is rubbed over a woollen towel and then taken near a stream of flowing water, the water stream bends towards the brush. Which of the following might be the reason for it?

1. Magnetic attraction by the charged brush
2. Water flowing under gravity acquires magnetic properties
3. Electrostatic discharge from the tap
4. Electrostatic force between the brush and the stream

Q.

What are charged objects? Give an example. [2 MARKS]

Q.

An uncharged conductor can be charged by _________ or ________ .

Q. ntThe force of repulsion between 2 point charges is F, when these are at a distance of 1 m apart. Now the point charges are replaced by spheres of radii 25 cm having the same charge as that of point charges and same distance apart. Then prove that the new force of repulsion will decrease.n

Q.

An inflated balloon is rubbed with woollen cloth and in another case, a ballpen refill is rubbed with polythene. When they were brought close, it is observed that they attract each other. What can we understand by this?

1. Both acquired same kind of charge

2. They acquired different kinds of charges

3. One of the object is not charged

4. None of these

Q.

In one case, an inflated balloon is rubbed with a woollen cloth and in another, a ballpen refill is rubbed with polythene. When they are brought closer, it is observed that they attract each other. What can we understand by this?

1. Both acquired same kind of charge

2. They acquired different kinds of charges

3. One of the object is not charged

4. None of these

Q.

When a glass rod is rubbed with a piece of silk cloth the rod

1. and the cloth both acquire positive charge.

2. and the cloth both acquire negative charge.

3. becomes negatively charged while the cloth has a positive charge.

4. becomes positively charged while the cloth has a negative charge.

Q.

Capacitor works through the process of

1. Induction

2. Convection

3. Conduction

4. Radiation

Q. How can we know that a object is chaerged positively or negatively ??

Q.

An inflated balloon is rubbed with a woollen cloth and in another case, a ballpen refill is rubbed with polythene. When they are brought closer, it is observed that they attract each other. Which of the following conclusions can be made from this?

1. They acquired different kinds of charges

2. Both acquired same kind of charge

3. One of the object is not charged

4. None of these

Q.

An inflated balloon is rubbed with a woollen cloth and in another case, a ball pen refill is rubbed with polythene. When they are brought closer, it is observed that they attract each other. What can we understand by this?

1. Both acquired same kind of charge

2. They acquired different kinds of charges

3. One of the object is not charged

4. None of these

Q. On a cold, dry day, a child takes two balloons and rubs them against his sweater.
(a) When taken near each other, the balloons repel each other.
(b) When one is taken near the wall, it sticks to it.
Give reasons for the above observations.

Q.

When a glass rod is rubbed with a piece of silk cloth, the rod:

1. becomes positively charged while the cloth has a negative charge.

2. and the cloth both acquire positive charge.

3. and the cloth both acquire negative charge.

4. becomes negatively charged while the cloth has a positive charge.